ACT 2008 Dodge Challenger Twin Disc HD Street Kit Clutch Kit

A Challenger with a six-speed manual and a supercharger, cam or a Hellcat tune will eventually overpower a single-disc clutch. ACT part number T1S-D03 is the Twin Disc Heavy Duty Street kit for the Challenger, built for owners who need far more holding power than stock but still want a car that drives in traffic. This listing is cataloged for the 2008 Challenger, and ACT's own application chart carries the same part number through later manual cars, covered in the fitment section below.

What the twin disc HD street clutch does in a Challenger

A twin disc stacks two friction discs with a floater plate between them inside one pressure plate, so the clamp load acts on twice the friction surface. ACT rates T1S-D03 at 891 ft-lb at the crank, which it lists as 89 percent over the original equipment clutch. The discs are 10.5 inch (267 mm) rigid-hub street discs made from a high-copper organic material with a steel-backed lining for burst strength, on a heat-treated chrome-moly hub that fits a 1.125 inch input shaft.

The floater uses ACT's Positive Lift Floater System, which lifts the middle plate off the discs on release with no posts to wear and no floater rattle. The kit adjusts for disc wear and spreads disengagement evenly across both discs. A CNC-machined, dynamically balanced flywheel is part of the kit, along with the pressure plate, both discs, the floater and an alignment tool. ACT notes that some kits also carry a pilot or release bearing, so check the box before you start. The whole kit weighs about 56 lb.

Symptoms that call for a twin disc upgrade

• Rpm climbs without the car pulling harder in third through sixth at full throttle
• Slip that began after a supercharger, a tune or sticky drag radials went on
• Hot friction smell after launches, burnouts or a road course session
• Chatter or shudder on takeoff from a glazed disc or a heat-checked flywheel
• A bite point that keeps moving higher in the pedal travel

How to confirm before you buy

Do a high-gear roll-on from about 2,000 rpm at full throttle and watch the tach against road speed. If rpm jumps ahead, the clutch is slipping. Rule out the hydraulics first: a weak slave or a soft, low pedal can keep the clutch from fully clamping, and oil from a rear main seal or the transmission front seal will ruin any disc you install. Our slipping diagnosis guide covers how to separate true slip from other drivetrain problems, and the manual versus automatic repair cost breakdown helps you budget the labor.

Fitment

Our listing is for the 2008 Dodge Challenger. Every 2008 Challenger left the factory as an SRT8 with a five-speed automatic, so on a 2008 this kit is for a car that has already been converted to the Tremec TR-6060 six-speed manual. ACT's application chart for T1S-D03 runs from the 2008 SRT8 through 2021 manual Challengers, including the 5.7 R/T, the 6.1 and 6.4 SRT8 and SRT 392, Scat Pack, T/A and the 6.2 SRT Hellcat. The chart skips the 2011 model year, so 2011 owners should send us the VIN before ordering. If your car has a swapped transmission or a non-stock bellhousing, send the year, engine and the last 7 of the VIN. More clutch kits are in our rebuild kits department.

Install notes

• Use the ACT flywheel supplied in the kit with new flywheel bolts torqued to the factory spec. The twin disc is built as a matched assembly.
• Stack the discs and floater in the order and direction shown in ACT's instructions, then center them with the supplied tool or a universal clutch alignment kit before snugging the cover bolts in a crisscross pattern.
• Replace the pilot bearing and release bearing if your kit does not include them, and inspect the slave cylinder while the transmission is out.
• Bleed the clutch hydraulics completely and set the pedal so the clutch fully releases.
• Expect pedal effort to rise. ACT puts its Heavy Duty pressure plates at 15 to 40 percent more effort than stock.
• Break the organic discs in for 300 to 500 miles of easy stop-and-go driving before any hard launches, per ACT.

While the interior is apart, many owners also fit a TR6060 weighted shifter handle for a cleaner throw.

Does this fit a 2015 or later Challenger Hellcat with the manual?

ACT's application chart lists T1S-D03 for 2015 through 2021 SRT Hellcat Challengers with the six-speed manual. Send us the VIN if you want us to double check your car.

My 2008 Challenger is an automatic. Can I use this?

Only after a manual conversion. All 2008 Challengers were built with a five-speed automatic, so this clutch is for 2008 cars that have been swapped to the TR-6060 six-speed.

Is the flywheel included?

Yes. ACT twin disc kits include a CNC-machined, balanced flywheel along with the pressure plate, two discs, the floater and an alignment tool.

Will it rattle or chatter like a race twin disc?

ACT describes the feel as light pedal effort and smooth engagement, with OE to mild gear rattle. The Positive Lift Floater System is designed to stop floater rattle.

How much torque will it hold?

ACT rates this kit at 891 ft-lb measured at the crank, 89 percent above the original clutch.

How long is the break-in?

ACT recommends 300 to 500 miles of mild stop-and-go driving for organic street discs before racing or hard driving, without overheating the clutch.

• Transmission Slipping Diagnosis Guide
• Automatic vs. Manual Transmission Repair Cost: What to Actually Expect
• Rebuild vs Replace vs Reman Transmission